Multi-Angle Snowflake Camera Value-Added Product Now Available

Published: 19 March 2017
Retrieved average of maximum dimension for a subset of particles that fell into each 5-minute wide time bin (top) and quality bits (bottom) for data captured between May 13 and May 19, 2016, are shown here.

The Multi-Angle Snowflake Camera (MASC) instrument provides high-resolution multi-angle imaging of hydrometeors in free fall with simultaneous measurement of fall speed. The MASC consists of three cameras, separated by 36 degrees, each pointing at an identical focal point approximately 10 centimeters away within a 20-centimeter wide ring through which hydrometeors fall.

Located immediately above each camera, LED lights illuminate the center of the depth of field for its corresponding camera. The instrument uses an infrared system to both measure hydrometeor fall speed, and trigger the cameras to capture image of the hydrometeor. This system relies on two sets of sensors arranged vertically (one set above the other) separated by 32 millimeter.

The MASC Particles value-added product provides analysis of images and fall speed data from the MASC ingest to provide a range of attributes including hydrometeor size, fall speed, orientation, and shape. Two MASC datastreams are produced:

  • c1: Data reported per particle
  • c1: 5-minute averages of particle data.

Data are available for the third ARM Mobile Facility deployment at Oliktok Point, Alaska.

Feedback and use of the data are welcomed and encouraged. For questions or to report data problems, please contact Laura Riihimaki. To access the data sets, please browse the MASC data in the ARM Data Archive. (Go here to create an account to download the data.)

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The ARM Climate Research Facility is a national scientific user facility funded through the U.S. Department of Energy’s Office of Science. The ARM Facility is operated by nine Department of Energy national laboratories.